Demirci Mehmet, Yiğin Akın, Ünlü Özge, Kılıç Altun Serap
Beykent University Faculty of Medicine, Department of Medical Microbiology, İstanbul, Turkey.
Harran University Faculty of Veterinary Medicine, Department of Genetics, Şanlıurfa, Turkey.
Mikrobiyol Bul. 2019 Jan;53(1):43-52. doi: 10.5578/mb.67468.
Hepatitis E virus (HEV) is one of the major foodborne viral pathogens transmitted through the fecal-oral route. Four genotypes of HEV are known to infect humans and it is reported that different types of HEV are active in zoonotic transitions. It is known that the HEV genotype 1 and HEV genotype 2 infections are generally acute and the HEV genotype 3 infections are chronic. Therefore, in the studies related to HEV infections, it is important to determine the genotypes to monitortreatment regimens. Although raw milk is often used in communities due to its low cost, there are limited data on the rates and the genotypes of HEV in our country and in the world. In light of this information, we aimed to investigate epidemiologically the quantity and genotypes of HEV RNA in 231 raw milk (48 cow milk, 65 goat milk, 65 sheep milk, and 53 donkey milk) samples. Viral RNAs were isolated from raw milk samples and the ORF2 region of HEV was investigated by the qRt-PCR method to determine quantitatively the presence of HEV RNA. In addition, among HEV RNA positive samples, the ORF2 region of HEV was amplified by nested PCR and the amplicons were sequenced. HEV RNA was detected in 47 (20.34%) raw milk samples, Positivity was detected in 14 (29.16%) of cow milk, 12 (18.46%) of goat milk, 8 of sheep milk (12.3) and 13 of donkey milk (24.5%). The amount of HEV RNA in cow milk found as the highest in both proportion and quantity. When the distribution of the HEV genotypes in the 47 positive samples was examined, 27 (57.44%) HEV genotype 1a, 10 (21.27%) HEV genotype 1b, 4 (8.5%) HEV genotype 4c, 2 (4.2%) HEV genotype 3a, (2.13) HEV genotype 1c, 1 (2.13%) HEV genotype 3e, 1 (2.13%) HEV genotype 3f and 1 (2.13%) HEV genotype 3g were determined. Although genotype 1a is more frequent, it has been revealed that different genotypes encountered in our country. In conclusion, it has been determined that HEV, one of the major foodborne viral agents, may be encountered in raw milk, and the genotypes that can cause infections in human are found especially in raw milk from animal sources. For the prevention of foodborne outbreaks, the presence of HEV in raw milk should not be ignored.
戊型肝炎病毒（HEV）是通过粪-口途径传播的主要食源性病毒病原体之一。已知有四种基因型的HEV可感染人类，并且据报道不同类型的HEV在人畜共患病传播中较为活跃。已知HEV基因型1和HEV基因型2感染通常为急性，而HEV基因型3感染为慢性。因此，在与HEV感染相关的研究中，确定基因型以监测治疗方案很重要。尽管生乳因其成本低而在社区中经常使用，但我国和世界上关于HEV的感染率和基因型的数据有限。鉴于此信息，我们旨在通过流行病学方法调查231份生乳（48份牛奶、65份羊奶、65份绵羊奶和53份驴奶）样本中HEV RNA的数量和基因型。从生乳样本中分离病毒RNA，并通过qRt-PCR方法研究HEV的开放阅读框2（ORF2）区域，以定量确定HEV RNA的存在。此外，在HEV RNA阳性样本中，通过巢式PCR扩增HEV的ORF2区域并对扩增子进行测序。在47份（20.34%）生乳样本中检测到HEV RNA，牛奶中阳性率为14份（29.16%），羊奶中为12份（18.46%），绵羊奶中为8份（12.3%），驴奶中为13份（24.5%）。牛奶中HEV RNA的含量在比例和数量上均为最高。当检查47份阳性样本中HEV基因型的分布时，确定有27份（57.44%）为HEV基因型1a，10份（21.27%）为HEV基因型1b，4份（8.5%）为HEV基因型4c，2份（4.2%）为HEV基因型3a，（2.13）份为HEV基因型1c，1份（2.13%）为HEV基因型3e，1份（2.13%）为HEV基因型3f，1份（2.13%）为HEV基因型3g。虽然基因型1a更为常见，但已发现我国存在不同的基因型。总之，已确定主要食源性病毒病原体之一的HEV可能存在于生乳中，尤其是在动物源性生乳中发现了可导致人类感染的基因型。为预防食源性疾病暴发，生乳中HEV的存在不容忽视。
